Page 249 - Becoming Metric Wise

240 Becoming Metric-Wise

Own field openness is zero if among all citations to the journal’s own
field, none is given to other journals in the field. It is one if all field
citations are given to other journals in the field.
We note that instead of journals one may use an author or a group of
authors. Similarly, instead of fields one may use country, institute, language, etc.

7.13.2 Affinity Indices
So (1990) further proposes the following affinity indices, constructed via
partial indicators D, E, and F. Again a fixed publication window is used.
D is the number of citations received by journal J in year Y from itself
(articles published in journal J) for articles published in J during the publi-
cation window.
E is the number of citations received by journal J in year Y from other
journals in the same field as J, for articles published in J during the publi-
cation window.
F is the number of citations received by journal J in year Y from other
journals from other fields as J’s field, for articles published in J during the
publication window.
Hence D 1 E 1 F is the total number of citations received by journal
J in year Y for publications published in J during the publication window.
The first affinity index is the journal’s self-cited rate in the year Y for
a given publication window. It is defined as:
D
(7.27)
D 1 E 1 F
Own-field affinity is defined as
E
(7.28)
D 1 E
It is the ratio of citations from other journals in the field over the
number of citations from all journals in the field (including the journal
J itself).
Other-field affinity is defined as:

F
(7.29)
D 1 E 1 F
It is the ratio of citations from journals not in J’s field over the number
of citations from all journals (including the journal J itself).